To use a tick generated by a timer as a system tick needed by an embedded operating system, an error generated in a new timer needs compensation. For example, in a timer generating a tick at a cycle of 1 msec by using a clock signal of 32768 Hz, the timer may generate a tick at a cycle of about 1.007 msec by counting a clock signal 33 times. Accordingly, an error of about 7 μsec is generated at a cycle of 1 msec and the error of a timer is accumulated as time passes. As a result, a difference between the system tick that the operation system recognizes and actual time is accumulated as well.
Thus, it is difficult to use the tick of a timer directly as a tick of the operating system. That is, only after the error generated by the timer is compensated, the tick of a timer may be used as a tick of the operating system. To compensate the error of the timer, a complicated algorithm is performed or sophisticated hardware is needed.